Caching: In-Memory vs. Distributed

Options you can choose from:

In-Memory Caching

The cache is stored directly in the application's own memory (e.g., a built-in memory cache in your code). Very fast access, but the cached data is only available within that single running application.

Distributed Caching

The cache is shared across multiple servers or instances (e.g., Redis Cluster, Memcached). Many servers can read and write the same cached data, and the cache keeps working even if one server goes down.

Decision questions

Answer honestly according to the current needs of the project and infrastructure.

1. What is the scope of your application?

Small or single server / instance Medium, several servers or containers Large system running on many servers at the same time

2. Do you need to share the cache between multiple nodes?

No, each server can have its own local cache Sometimes, some data is shared Yes, all caches must be synchronized

3. How critical is data availability?

Not critical — it's acceptable if cached data is occasionally lost or unavailable Moderate, occasional loss is tolerable High — the cache must always be available, even if one server goes down

4. What type of data do you store in the cache?

Small and local for each server (e.g., computed values, user session data) A combination of local and shared data Large or shared datasets requiring centralization

5. What is your team's experience with caching tools?

Small team, experience only with simple in-memory cache Experience with basic distributed caching Experienced team, can handle Redis Cluster or Memcached Cluster

6. Do you need your application to run on multiple servers at the same time?

No — the application runs on a single server Sometimes — may occasionally need to run on multiple servers Yes — the application must run on many servers at the same time

Result

Based on your answers, see the recommended solution below. 👇

Important note

Feedback & Sharing

Give us your thoughts on this page, or share it with others who may find it useful.

Share with your network:

Feedback

Found this helpful? Let me know what you think or suggest improvements 👉 Contact me.